桃蚜最佳人工全纯饲料的筛选

【目的】为了明确不同营养组分配方的人工全纯饲料对桃蚜Myzus persicae(Sulze)生长发育的影响,筛选出适合室内饲养桃蚜的人工饲料配方。【方法】本文以5组不同浓度的氨基酸溶液(A1=50 mmol/L、A2=100 mmol/L、A3=150 mmol/L、A4=200 mmol/L、A5=250 mmol/L)和4组不同浓度的蔗糖混合液(S1=250 mmol/L、S2=500 mmol/L、S3=750 mmol/L、S4=1 000 mmol/L)组配的混合液饲喂桃蚜,测定了桃蚜的存活率、存活时间、平均产仔量和产仔率,并利用生命表技术,分析不同处理对桃蚜实验种群生命参数的影响。【结果】结果表明,不同饲料配方对桃蚜的存活及繁殖均有一定的影响。存活率以A1S3、A1S4和A3S4最高,三者之间差异不显著(P>0.05);存活时间以A1S3、A1S4和A3S4最长,分别达到了(34.00±1.00)d、(33.33±1.15)和(30.6±4.04)d,三者之间差异不显著(P>0.05);平均产仔量和产仔率以A3S1和A3S4的最大,A3S1分别达到了(9.75±2.71)头/成蚜和43.33%±15.28%,A3S4分别达到了(9.43±2.27)头/成蚜和50.00%±10.00%,二者之间差异不显著(P>0.05)。种群生命参数中,A3S1和A3S4的净生殖率分别达到了(4.43±2.31)和(4.63±1.25),二者之间差异不显著(P>0.05),与其他饲料配方差异显著(P<0.05)。【结论】综合所有参数比较,确定A3S4为桃蚜的最佳人工饲料配方。     

盐碱胁迫对柳树幼苗生长和渗透调节物质含量的影响

以盐柳1号为试验材料,将2种中性盐NaCI、Na_2SO_4和2种碱性盐NaHCO_3、Na_2CO_3,按不同比例混合成A(NaCl∶Na_2SO_4∶NaHCO_3∶Na_2CO_3=1∶2∶1∶0)、B(NaCl∶Na_2SO_4∶NaHCO_3∶Na_2CO_3=1∶9∶9∶1)、C(NaCl∶Na_2SO_4∶NaHCO_3∶Na_2CO_3=1∶1∶1∶1)3种组合,设4个浓度梯度(50、100、150、200 mmol/L),模拟出12种盐度和碱度各不相同的盐碱条件,对盐柳1号幼苗进行处理,测定了株高生长量、丙二醛(MDA)含量、脯氨酸含量和可溶性糖含量4项指标。结果表明:随着盐浓度的增大和碱性盐比例的增高,盐柳1号幼苗的株高生长量呈降低趋势,叶片MDA、脯氨酸和可溶性糖含量则有不同程度的升高。A、B、C处理组的株高生长量在盐浓度200 mmo/L时分别相对CK降低了61.32%、68.67%、73.02%,差异均达到显著水平(P0.05)。A处理组(pH值为8.04),随着盐浓度的增大,叶片MDA、脯氨酸和可溶性糖含量升高趋势不明显;B处理组(pH值为8.66),叶片MDA含量在盐浓度超过100 mmol/L时呈显著升高趋势,脯氨酸和可溶性糖含量在盐浓度超过150 mmol/L时急剧增加;C处理组(pH值为9.47),盐浓度大于150 mmol/L时,盐柳1号幼苗的叶片全部枯黄。综合分析结果表明,在混合盐碱胁迫下,盐柳1号幼苗的生长受到了不同程度的抑制;盐柳1号可以耐受不超过100 mmol/L的3种组分盐碱胁迫,且盐浓度150 mmol/L、pH9.51的盐碱条件不适宜盐柳1号的生长。     

外源硫化氢和水杨酸对盐胁迫下加工番茄幼苗生长与生理特性的影响

以加工番茄KT-7为材料,在水培条件下,研究外源水杨酸(SA,0.15 mmol/L)、硫化氢(H2S)供体硫氢化钠(NaHS,50 mmol/L)对150 mmol/L NaCl胁迫下加工番茄幼苗的渗透调节、活性氧代谢和快速叶绿素荧光的影响,以探讨H2S和SA这2种信号分子协同作用、以及实际生产中缓解加工番茄幼苗盐胁...     

外源水杨酸对盐胁迫下大黄种子萌发及幼苗生长的影响

该研究以掌叶大黄、唐古特大黄和药用大黄种子为材料,采用双层滤纸培养法,设置系列浓度NaCl (0、100、150、200、250 mmol/L) 胁迫试验,以及系列浓度水杨酸(SA)溶液(0、50、100、150、200、250 mg/L)拌种和浸种后盐胁迫实验,测定3种大黄种子萌发及幼苗生长指标,揭示外源水杨酸对盐胁迫下大黄种子萌发及幼苗生长的影响。结果显示：(1)随NaCl浓度增大3种大黄种子的发芽率均呈直线下降趋势,且子叶、胚轴、根和苗等生长均受到强烈抑制。(2)在拌种条件下, 200 mmol/L NaCl胁迫下掌叶大黄苗长在200 mg/L SA处理下受到显著促进; 200 mmol/L NaCl浓度盐胁迫下唐古特大黄种子发芽率在250 mg/L SA处理下受到显著抑制;100 mmol/L NaCl胁迫下药用大黄种子发芽势在200 mg/L SA处理下受到显著抑制,其发芽率在150 mg/L SA处理下得到显著抑制,其苗长在250 mg/L SA处理下受到显著抑制。(3)在浸种条件下, 200 mmol/L NaCl胁迫下掌叶大黄种子发芽率在50 mg/L SA处理下显著提高,其幼苗根长和苗长的生长在250 mg/L SA处理受到显著促进;200 mmol/L NaCl胁迫下唐古特大黄种子的发芽势在200 mg/L SA处理下得到显著促进,其幼苗根和苗的生长在50 mg/L SA处理下得到显著促进;100 mmol/L NaCl 胁迫下药用大黄根和苗的生长在100 mg/L SA处理下均得到显著促进。研究表明,3种大黄种子和幼苗对盐胁迫的响应趋势一致,但对不同浓度SA拌种和浸种的响应有较大差异。     

发菜藻蓝蛋白分离纯化的研究

以发菜为材料,比较了提取液类型和饱和硫酸铵浓度对藻蓝蛋白提取的影响,并对藻蓝蛋白的提取程序和部分特性进行了研究。结果表明:50 mmol/L KP缓冲液(pH值7.2)是合适的提取液,体积分数为40%~50%饱和硫酸铵盐析效果优于其它浓度。经过DEAE-Toyopeal 650 S离子交换层析和SuperdexTM200凝胶过滤层析后,藻蓝蛋白纯度达6.2,最大吸收峰位于615 nm,荧光发射峰位于649 nm,由α和β2个亚基组成,其分子质量分别为18 051.17和19 142.27 Da。因此,发菜藻蓝蛋白分离纯化较为理想的程序为:藻粉→50 mmol/L KP缓冲液(pH值7.2)浸泡→French pressure(1 500 kg/cm2)破碎细胞→40%~50%饱和硫酸铵盐析→DEAE-Toyopeal 650 S离子交换层析→SuperdexTM200凝胶过滤层析→较纯的藻蓝蛋白。     

盐胁迫下囊果碱蓬出苗状况及苗期抗盐性

研究了盐胁迫对囊果碱蓬出苗、幼苗生长、离子积累以及光合放氧速率的影响.囊果碱蓬生长的最适盐浓度在200 mmol/L NaCl左右.高浓度NaCl(400 mmol/L和600 mmol/L)没有显著降低其出苗率,200 mmol/L NaCl对出苗率具有促进作用.400 mmol/L和600 mmol/L NaCl显著降低了光合放氧速率.囊果碱蓬在高浓度NaCl处理下能够维持叶片较高的K+/Na+ 及含水量可能是其适应高盐生境的重要机制.     

血管平滑肌细胞的体外氧化应激反应及雌激素的影响

目的探讨雌激素对VSMC氧化应激反应的影响及机制。方法第3-4代雌性大鼠血管平滑肌细胞(VSMC)在有或无10-8mol/L 17b-雌二醇(E2)存在下用不同浓度(0-250mmol/L)H2O2诱导氧化应激;MTT法,流式细胞术,Western blot分别检测VSMC活力,细胞周期,MAPK信号通路活性的变化。结果当浓度低于25mmol/L时,H2O2对VSMC活力无影响;当浓度为50-150mmol/L时,VSMC活力呈剂量依赖性下降,并伴随G0/G1期细胞升高;当浓度达到200mmol/L时,细胞活力下降至最低点并出现凋亡峰。10-8mol/L E2可显著抑制150mmol/L H2O2诱导的VSMCERK和p38的磷酸化、从而缓解VSMC G0/G1期阻滞,并降低高浓度H2O2诱导的VSMC凋亡。结论中等浓度的H2O2(50-150mmol/L)抑制VSMC增殖;高浓度H2O2(≥200mmol/L)不仅抑制VSMC生长、且导致部分VSMC凋亡;雌激素可通过抑制ERK和p38活性对氧化应激的VSMC起保护作用。     

高效液相色谱法测定附子及其炮制品中三种双酯型生物碱

本文建立了一种能同时检测附子及其炮制品中乌头碱、新乌头碱和次乌头碱含量的HPLC-DAD检测方法。采用的色谱柱为Hepersil BDS C18分析柱(150 mm×4.6 mm ID,5μm),流动相为40 mmol/L乙酸铵(浓氨水调pH10.0)(A)-乙腈(B)梯度洗脱,检测波长为240nm,流速为1 mL/min。乌头碱、新乌头碱、次乌头碱的线性范围分别为0.0232-2.32μg、0.0216-2.16μg、0.0214-2.14μg(r=0.999976、0.999992、0.999994,n=6);加样回收率为96.4-103.5%(n=6),RSD均小于2.3%。测定结果表明7批不同产地附子生品及16批由同一产地生附子制得的炮制品中三种双酯型生物碱的含量差异悬殊,该方法为附子质量标准和炮制工艺规范的制定及进一步的药效学研究提供了可靠的数据和方法学平台。     

RP-HPLC测定红丝线提取物中紫蓝素的含量

建立了红丝线提取物中紫蓝素的测定方法。采用反相高效液相色谱法,色谱柱为ZORBAXXDB-C18(4.6mm×150mm,5μm);流动相:V(乙腈):V[75mmol/L乙酸铵+0.5mmol/LEGTA(pH7.0)]=8∶92;流速:1mL/min;检测波长590nm。紫蓝素的线性范围为2.5～50mg/L(r=0.9999),回收率97.9%～101.5%。该法简便、准确,重复性好,适用于测定红丝线提取物中紫蓝素的含量。     

微流控芯片电泳分离血清高密度脂蛋白亚类的研究

描述了一种微流控芯片电泳快速分离血清高密度脂蛋白(high density lipoprotein,HDL)亚类的方法.利用自制的微流控芯片,结合激光诱导荧光检测系统,40mmol/L Tricine、50mmol/L甲基葡胺(MEG)、0.2mmol/LSDS(pH8.5)为样品缓冲液,40mmol/L Tricine、50mmol/LMEG、0.01mmol/L SDS(pH8.5)为分离缓冲液,4min内HDL3和HDL2两种亚类得到基线分离.该法操作过程简单,重复性较佳,测试费用低廉,在临床HDL亚类的检测中具有较好的应用前景.     

Osmotic Stress Increases Alcohol Dehydrogenase Activity in Maize Seedlings

Maize (Zea mays L.) seedlings were exposed to osmotic stress, and alcohol dehydrogenase (ADH) activity and abscisic acid (ABA) concentration were determined. The osmotic stress increased ADH activities in both roots and shoots, whereas the increase was 2-fold greater in roots than the shoots. The stress also increased ABA concentration in both roots and shoots and the increase was greater in the roots than in the shoots.     

Transgenic Plants of Creeping Bent Grass Harboring the Stress Inducible Gene, 9-cis-epoxycarotenoid dioxygenase, are Highly Tolerant to Drought and NaCl Stress

Transgenic lines of creeping bent grass were generated by Agrobacterium-mediated transformation with the VuNCED1 which was cloned from cow pea has a homology to 9-cis-epoxycarotenoid dioxygenase, which is supposed to be involved in abscisic acid (ABA) biosynthesis. ABA, a cleavage product of carotenoids, is involved in stress responses in plants. The limiting step of ABA biosynthesis in plants is presumably the cleavage of 9-cis-epoxycarotenoids, the first committed step of ABA biosynthesis. Molecular analyses of transgenic lines as performed by Southern hybridization genomic DNA-PCR revealed integration of the VuNCED1. Challenge studies performed with transgenic plants by exposure to salt stress (up to 10 dS m⁻¹) and water stress (up to 75%) for 10 weeks, revealed that more than 50% of the transgenic plants could survive NaCl and drought stress whereas wild-type was not. ABA levels were measured under drought and normal conditions, endogenous ABA was dramatically increased by drought and NaCl stress in transgenic plants. These results indicate that it is possible to manipulate ABA levels in plants by over expressing the key regulatory gene in ABA biosynthesis and that stress tolerance can be improved by increasing ABA levels. Chenna Reddy Aswath and Sun Hyung Kim - First two authors contributed equally to this work     

Chilling Induced Oxidative Stress in Germinating Wheat Grains as Affected by Water Stress and Calcium

Wheat (Triticum aestivum L.) plants were subjected to mild water stress during grain filling at milk (early, medium, and late) and dough (early, soft, hard) stages. The grains harvested from stressed plants were subjected to low temperature stress of 10 °C for 24 h in presence or absence of 1 mM CaCl₂, and embryos were examined for oxidative injury. The embryos of grains water stressed at milk and soft dough stages showed lowest contents of H₂O₂ and malondialdehyde and highest membrane stability index, ascorbic acid content, and activities of catalase, ascorbate peroxidase, and superoxide dismutase as compared to control embryos or water-stressed at other stages. Presence of Ca²⁺ in the medium reduced H₂O₂ and malondialdehyde content and increased ascorbic acid content, and catalase, ascorbate peroxidase and superoxide dismutase activities.     

Stress response to cold in Trichinella species

Trichinella-type larvae (L(1)) are found in the muscles of infected wild animals and domestic pigs and are the cause of trichinosis in man and other animals throughout the world. These parasites are exposed to low temperatures during their life cycle. On this premise, three Trichinella species of different types of habitat (the arctic T. nativa, the cosmopolitan T. spiralis, and the tropical T. nelsoni) were selected to examine the effect of a shift in temperature, from 37 to 4 degrees C, on long-term survival. Evaluation was then made of whether these effects were related to differential protein synthesis and/or heat shock protein (Hsp) expression. Test samples at 0, 2, 4, or 8 h and 1, 5, or 9 days after the temperature shift were obtained and subjected to Hsp determination by Western blotting. Total protein changes were explored by SDS-PAGE followed by densitometric analysis of the gels. During the "acclimatization phase" (at 2, 4, and 8 h), a different total protein and a depressed Hsp expression pattern were shown in each Trichinella species. Following acclimatization, Hsp70, but not Hsp60 or Hsp90, markedly increased above control levels in the three species, indicating a role for this Hsp as a classic stress protein. The synthesis of a 50-kDa Hsp was significantly induced in T. spiralis larvae, suggesting its potential function as a cold shock protein in this species.     

Improved Performance of Transgenic Glycinebetaine-Accumulating Rice Plants under Drought Stress

Plasmid DNA (pChlCOD), containing the selectable hygromycin phosphotransferase hpt gene for hygromycin B resistance and the Arthrobacter globiformis codA gene for choline oxidase which catalyzes the direct conversion of choline to glycinebetaine, was delivered into rice plants using Agrobacterium-mediated gene transfer via scutellum-derived calli. Southern, Northern and Western blot analyses demonstrated that the foreign gene had been transferred, integrated into rice chromosomal DNA and expressed. Drought test indicated that glycinebetaine acts as an osmoprotectant and its production in transgenic rice plant helped the cells to maintain osmotic potential and increased root growth, and thus enhanced the ability of the plants to tolerate water deficit This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermoluminescence Investigation of Low Temperature Stress in Maize

The thermoluminescence (TL) emission of photosynthesising materials originates from the recombination of charge pairs created by a previous excitation. Using a recently described TL set-up the effect of chilling stress on TL bands occurring at positive temperatures (AG, B, and HTL) was investigated in intact leaves. The far-red irradiation of leaves at low, but non-freezing temperatures induced a TL band peaking at around 40–45 °C (AG band), together with a B band peaking between 20 and 35 °C. Low temperature stress first caused a downshift and a temporary increase in the AG band after 4 h at 0 °C in the light, then a decrease in the AG and B TL bands after 1 d at 0 °C in the light. This decrease was less pronounced in cold-tolerant genotypes and in those grown at acclimating temperatures. Furthermore, an additional band appeared above 80 °C after severe cold stress. This band indicates the presence of lipid peroxides. Thus TL is a useful technique for studying the effects of low temperature stress.     

Heat Stress and Spermidine: Effect on Chlorophyll Fluorescence in Tomato Plants

Two tomato (Lycopersicon esculentum L.) cultivars: Robin (tolerant) and Roma (sensitive to heat stress) were studied. Chlorophyll fluorescence induction parameters (F_v/F_p, A_max, and Rfd) at 25 °C showed that the PS2 activity was similar for both cultivars. The parameters, measured at 38 °C, decreased in both cultivars, but more in cv. Roma. Exogenous application of 4 mM spermidine improved the plant heat-resistance in both cultivars, and especially in cv. Roma. Analysis of chlorophyll fluorescence changes during linear increase in temperature showed that cv. Robin plants have higher ability to hardening and higher resistance to thermal damage of the pigment-protein complexes structure and the activity of PS2 than cv. Roma.     

海水胁迫对菠菜叶绿素代谢的影响

以耐海水品种‘荷兰3号’和海水敏感品种‘圆叶菠菜’为试验材料,采用营养液栽培,研究海水胁迫对菠菜叶绿素代谢的影响。结果表明,海水胁迫下,2个菠菜品种叶片的叶绿素a(Chl a)、叶绿素b(Chl b)和总叶绿素含量以及叶绿素合成前体———原叶绿素酸(Pchl)、镁原卟啉IX(Mg-proto IX)、原卟啉IX(Proto IX)和尿卟啉原III(UroIII)含量均明显降低,而胆色素原(PBG)和δ-氨基酮戊酸(ALA)积累,‘圆叶菠菜’的变化幅度大于‘荷兰3号’。海水胁迫下,‘荷兰3号’叶片的叶绿素酶(Chlase)活性无显著变化,胆色素原脱氨酶(PBGD)和尿卟啉原III合酶(UROS)活性在胁迫第3天显著下降,而‘圆叶菠菜’Chlase活性显著上升,PBGD和UROS活性显著下降。研究发现,在海水胁迫条件下,菠菜叶片的叶绿素合成代谢受阻,受阻位点位于PBG→UroIII的转化过程,其中‘圆叶菠菜’的受阻程度大于‘荷兰3号’;耐海水品种‘荷兰3号’叶片叶绿素含量降低主要由叶绿素合成代谢受阻引起,而海水敏感品种‘圆叶菠菜’叶绿素含量的降低则是由叶绿素合成受阻和叶绿素降解共同作用的结果。     

干旱胁迫对小紫珠光合生理的影响

以小紫珠(Callicarpa dichotoma)幼苗为试验材料,采用盆栽控水法设置4个水分梯度,分别为田间最大持水量的95%(对照)、75%(轻度干旱)、55%(中度干旱)和35%(重度干旱),研究土壤水分对小紫珠光合参数的影响。结果显示:(1)随着干旱胁迫的加剧,小紫珠的净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)和水分利用效率(WUE)逐渐下降,其胞间CO_2浓度(C_i)在轻度和中度干旱胁迫下逐渐下降,在重度干旱胁迫下显著升高。(2)随着干旱胁迫的加剧小紫珠的光饱和点(LSP)、最大净光合速率(Pnmax)、暗呼吸速率(Rd)和表观量子效率(AQY)显著减少,光补偿点(LCP)极显著增加(P0.01)。(3)随着胁迫程度的增加,小紫珠的最大荧光(F_m)、最大光化学效率(F_v/F_m)和PSⅡ的量子效率(Fv/Fo)逐渐减少,初始荧光(Fo)显著升高(P0.01);随着干旱胁迫的加剧小紫珠能量分配比率参数φPo、Ψo、φEo逐渐下降,φDo逐渐增加;代表单位反应中心活性的参数ABS/RC、TRo/RC、ETo/RC和DIo/RC逐渐升高。(4)随着胁迫程度的增加,小紫珠叶绿素a、叶绿素b、叶绿素总量和叶绿素a/b逐渐减少。研究表明,干旱胁迫下小紫珠光合速率的降低既有气孔因素也有非气孔因素,但轻度和中度干旱胁迫下以气孔限制为主,而在重度干旱胁迫下以非气孔限制为主。